This project will study a method of producing graded levels of periodontal surgical pain, induced under controlled and standardized conditions, and will test the sensitivity and resolving power of that method both for discriminating known differences in analgesic potency and for studying the influence of personal variables on the pain response. A questionnaire will be developed to predict individual responses to pain by using self-report information concerning psychological characteristics. Stability of individual differences in tolerance for pain induced by each of our four procedures (periodontal, radiant heat, electric shock, and tourniquet) will be studied to clarify the status of pain tolerance as a possible general behavior trait; and the reliability and analytic resolving power of a multimethod approach that utilizes all four of those procedures for inducing pain will be tested. Subjects will be healthy college-age volunteers who are studied with questionnaires and with laboratory procedures for inducing and evaluating pain. Standard univariate and multivariate analytic procedures will be used to evaluate results.